Matplotlib数据二维绘图实践

通过 Matplotlib 绘制出下图这副图像

Code

from matplotlib import pyplot as plt
import numpy as np
#尺寸_figsize，分辨率_dpi
plt.figure(figsize=(8, 5), dpi=80)
axes = plt.subplot()
#顶部和右侧边框设为隐藏
axes.spines['top'].set_color('none')
axes.spines['right'].set_color('none')
#设置xy轴位置
axes.xaxis.set_ticks_position('bottom')
axes.spines['bottom'].set_position(('data', 0))
axes.yaxis.set_ticks_position('left')
axes.spines['left'].set_position(('data', 0))
#xy数据
x=np.linspace(-1*np.pi, np.pi, 1000)
ys=np.sin(x)
yc=np.cos(x)
axes.plot(x, ys, color='red', linestyle='-', linewidth=2.5, label='Sin Function')
axes.plot(x, yc, color='blue', linestyle='-', linewidth=2.5, label='Cos Function')
#限制xy
plt.xlim(x.min()*1.1, x.max()*1.1)
plt.ylim(ys.min()*1.1, ys.max()*1.1)
#标注xy轴
plt.xticks([-np.pi, -np.pi / 2, 0, np.pi / 2, np.pi],
           [r'$-\pi$', r'$-\pi/2$', r'$0$', r'$+\pi/2$', r'$+\pi$'])
plt.yticks([-1, 1],
          [r'$-1$', r'$+1$'])
t=np.pi*2/3
ts=np.sin(t)
tc=np.cos(t)
#标记点
plt.scatter(t, ts, linewidth=1.5, color='red')
plt.scatter(t, tc, linewidth=1.5, color='blue')
plt.plot(np.ones(100)*t, np.linspace(0, ts, 100), linestyle='--', color='red', linewidth=1.5)
plt.plot(np.ones(100)*t, np.linspace(tc, 0, 100), linestyle='--', color='blue', linewidth=1.5)
# 增加箭头标注
plt.annotate(r'$\sin{(\frac{2\pi}{3})}=\frac{\sqrt{3}}{2}$',#Latex
             xy=(t, ts), xytext=(+10, +30), textcoords='offset points', fontsize=16,
             arrowprops=dict(arrowstyle="->", connectionstyle="arc3,rad=.2"))
plt.annotate(r'$\cos{(\frac{2\pi}{3})}=-\frac{1}{2}$',
             xy=(t, tc), xytext=(-90, -50), textcoords='offset points', fontsize=16,
             arrowprops=dict(arrowstyle="->", connectionstyle="arc3,rad=.2"))
axes.legend(loc='upper left',frameon=False)
plt.show()

前置知识

ax.spines——matplotlib坐标轴设置
matplotlib.pyplot.annotate